Fix the same bug as in procfs_doproc{,db}regs(): check that uio_offset is 0 upon entry, and don't reset it before returning.
Fix the same bug as in procfs_doproc{,db}regs(): check that uio_offset is
0 upon entry, and don't reset it before returning.

MFC after:	3 weeks

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase